The present invention concerns a novel power system for an implantable heart pump.
A most important consideration with implanted artificial heart pumps and their associated control and power systems are reliability and safety. They must be capable of working properly for extended periods of time without replacement of implanted parts. All parts and systems as used must be biocompatible. They must be capable of use without impeding the proper circulation and functioning of blood through clotting or cell damage.
Also of great importance are quality of patient life considerations. The implanted pump and control and power system must be small and preferably without any wires or other structures protruding through the skin. The system must interfere with normal patient activities to the minimum extent possible. Therefore, the system should be capable of functioning for at least limited periods of time with untethered operation so that the patient may bathe comfortably and engage in other activities. Any external components must be easy and comfortable for the patient to use on his own.
One major consideration relates to redundancy in the power and control system. A certain amount of redundancy especially as to parts, such as batteries and motors, is essential in order that the system meet safety requirements. Therefore, systems that lack any redundancy are not considered acceptable. On the other hand, too much redundancy even including those components extremely unlikely to fail can add unnecessary size, complexity and cost to a system.
It is therefore an object of the present invention to provide a power and control system that is reliable and safe, without requiring unnecessary redundancy. The advantages of the present invention will become apparent as the description proceeds.
In accordance with the present invention, a novel implantable blood pump is provided. The pump includes a pump housing, a rotor mounted for rotation within the housing with the rotor having an elongated shaft portion and an impeller, and first and second stators for aiding in rotation of the impeller. A stator driver is provided for driving the stators. The pump also includes a microprocessor, and first and second batteries. The batteries, microprocessor and driver are interconnected and programmed so that during normal operation only one of the batteries is in use at a time for powering both stators simultaneously.
As used herein, a xe2x80x9cbatteryxe2x80x9d comprises a single sell or plurality of cells which are connected together to operate as a unit.
In the illustrative embodiment, the driver comprises two stator drivers. A multiplexer is provided for coupling the drivers to the stators in a desired manner, although it is preferred that only one driver be used during normal operation for driving both stators.
In the illustrative embodiment, the system includes an external transcutaneous energy transmission coil and an external power source. The system may also include an external monitor.
In one embodiment, the invention concerns a method for controlling the drive system for an electrical, implantable heart pump. It includes the steps of providing first and second batteries, a microprocessor, a transcutaneous energy transmission coil, a driver, and first and second stators, and using only one of the batteries at a time during normal operation of the system to power both stators simultaneously.
A more detailed explanation of the invention is provided in the following description and claims and is illustrated in the accompanying drawing.